Like @smilingstone mentioned, I am worried that there's some agency predation going on here. If it's the agency asking for pictures in lieu of other evidence, then there's immediate concern that they are not well versed in this process. I highly encourage you to focus on joining the community here. We're all in different stages of this journey and believe me, it does not end with filing the K1.
Bottom line is, you and your future spouse need to learn to advocate for yourselves for the entire journey. If there are complications, an immigration lawyer is advised. If everything is cut and dry though, believe that you can do this. The greatest effort is in gathering information, which no agency can do for you. Anything else that scares or overwhelms you, let us help you through it.